Related Articles

Many viral, bacterial and fungal diseases can infect cucumbers (Cucumis sativus) and green beans (Phaseolus vulgaris), but only a handful are common. There are no cures for most of the diseases that affect these vegetables, so prevention is key to keeping your plants healthy. In addition to planting disease-resistant varieties, plant both cucumbers and green beans in full sun, in well-draining loam soil. Proper growing conditions increase vigor and allow plants a better shot at fighting off disease. Beans are annual plants that thrive in U.S. Department of Agriculture plant hardiness zones 3 through 10 and cucumbers grow in zones 4 through 11.

Bacterial Wilt

Bacterial wilt is a fatal disease spread by cucumber beetles and other beetles. It can affect all cucurbits, causing wilting leaves and stunted growth. Once cucumbers are infected, there is no cure and the vines collapse and die within a few days. Focus on prevention, covering newly planted cucumbers with floating row covers to keep out beetles. Remove the covers once temperatures rise above 75 degrees and the plants begin to flower.

Powdery Mildew

Powdery mildew is a fungal disease that causes a white powdery coating to form on the leaves, stems and in severe case, the fruit of cucumber plants. Powdery mildew usually occurs in late summer in hot, humid conditions. Prevent it by spacing plants so air circulates freely and use soaker hoses instead of overhead sprinklers. Plant disease resistant varieties, such as "Marketmore 76" (Cucumis sativus "Marketmore 76") or Slicemaster (Cucumis sativus "Slicemaster"), hardy in USDA plant hardiness zones 4 through 11.

Cucumber Mosaic Virus

Cucumber mosaic virus causes mottled yellow and green leaves, stunted growth and spots or lines on developing fruit. There is no cure for infected plants. Disease-resistant varieties include "Marketmore 76," "Slicemaster" and "Sweet Success" (Cucumis sativus "Sweet Success"). Remove and destroy any infected plants. Aphids spread the disease, so controlling them might prevent infections. You can remove any weeds from near your garden that might harbor the pests and spray plants with a steady stream of water. You can also try coating both the tops and undersides of the leaves with an insecticidal soap or oil on overcast, cool days.

Bacterial Blight and White Mold

Bacterial blight and white mold are two common diseases that affect beans. Bacterial blight causes stunted growth and spotted leaves and beans, while white mold causes a white growth to form on the leaves, stems and beans. Both can be minimized through proper care, such as planting beans so air circulates freely and using soaker hoses instead of overhead sprinklers to keep the leaves dry. Remove any diseased plants promptly, completely clean up the garden in the fall and rotate bean crops so they don't grow in the same place year after year.

Bean Mosaic Virus

The bean mosaic virus can live in the soil for many years and is spread through infected weeds or seeds. Infected plants have mottled, twisted or deformed leaves, stunted growth and damaged beans. Disease-resistant varieties include "Blue Bush 274" (Phaseolus vulgaris "Blue Bush 274"), "Lancer" (Phaseolus vulgarus "Lancer") and "Tendercrop" (Phaseolus vulgaris "Tendercrop"). All of the above varieties grow in USDA plant hardiness zones 3 through 10. Infected plants must be removed and destroyed. Aphids can spread the disease, so spray them off with a steady stream of water or spray the leaves with an insecticidal soap or oil, coating each leaf thoroughly. (ref. 7)

About the Author

Julie Christensen is a food writer, caterer, and mom-chef. She's the creator of MarmaladeMom.org, dedicated to family fun and delicious food, and released a book titled "More Than Pot Roast: Fast, Fresh Slow Cooker Recipes."